Safety means for the door of an elevator



M. ETTER 3,075,61 7 SAFETY MEANS FOR THE DOOR OF AN ELEVATOR Jan. 29, 1963 Filed March 28, 1961 Fig.2

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3,075,617 SAFETY MEANS FOR THE DOGR (BE AN ELEVATQR Marcel Etter, Carouge-Geneve, Switze land, assignor to The present invention relates to a safety means between the stationary and the movable door part of the shaft door of an elevator, comprising a device for checking the closing and locking of the door, whereby the electric signals for the elevator control are controlled by at least one of the two devices by means of contactless switching elements.

The electric failing of control parts in the elevator control, due to short-circuits, sticking of relay contacts or the like and more particularly in the door contact circuit may result in the operation of the locking bolts of the door lock of a shaft door in the sense of locking with the door open. This may lead to accidents and in order to prevent such accidents the door locks have recently been provided with electro-mechanical means rendering impossible such so-called faulty closing of the door lock.

In a known device of this type the closing position of a shaft door is checked by a feeler pin, 'whereby the means connected with this pin prevents the production of the signal for the check of the closing position of the locking bolt.

The mentioned eleotro-mechanical measures for preventing faulty closing require additional expenses. Also all these devices undergo certain wear so that their safe operation is only guaranteed if they are periodically inspected.

it is a prime object of the present invention to provide a means for a door lock that prevents faulty closing and that has no movable mechanical parts, but in which the signal for the door lock is controlled magnetically. This is obtained by influencing a body of magnetically saturable material having a winding thereon, by a magnetic system secured in the movable door part, whereby the magnetic flux flowing over the locking bolt, the saturable body and the air gap between the stationary and the movable door part produces at least a partial saturation of the body, the effect of the saturation and the resulting signal being modified by the movement of the locking bolt only when the bolt has already locked the movable door part.

Preferably four anisotropic permanent magnets enclosing the locking bolt projecting into the movable door part are arranged with radial flux direction to the bolt, one of the two polarities being connected with ground.

For the manufacture and for the assembling of a door it is economically advantageous to house the closing and locking check devices of the door in the same casing. In the arrangement according to the invention the magnets for checking the closing and locking are lodged in the movable door part. Preferably this arrangement is such that one of the two polarities of the anisotropic permanent magnet systems for checking the closing and locking of the door are connected to a common ground.

Other features and advantages of the invention will become apparent from the description now to follow, of a preferred embodiment thereof, given by way of example only, and in which reference will be made to the accompanying drawings, in which:

FIGURE 1 is a section through the door lock in front View, and

FIGURE 2 is a side view of the door lock.

Patented Jan. 2%, lhi'ES ice Referring to the drawing, reference numeral 1 designates the movable door part, for example the door leaf and reference numeral 2 the stationary door part, for example the door post, of the shaft door of an elevator. Both of these door parts are made of a magnetically conductive material. A lock casing 2b of non-magnetic material is secured to the door post 2 by means of screws 3. A bushing 4 of non-magnetic material is pressed into the casing 29 and protrudes through an opening 5 in the door post 2 so that the front surface of the bushing 4 lies flush with the outer surface of the door post 2. This bushing serves, together with a bearing 25' in the casing 20, as a guiding for a locking bolt 23. A bolt lever 21 movably secured to the casing 20, is adapted for cooperating with the locking bolt 23 and lever 21. is actuated in a known way by a guide rail secured to the elevator cabin.

An angle member 31 of magnetically conductive material is secured by screws 38 to the casing 2% in such manner that it protrudes through an opening 2.9 in the casing and contacts the door post 2. An element 32 for checking the position of the locking bolt is connected to the angle 31. Element 32 comprises a ring core 33 of magnetically saturable material and a winding 34 on the core. On both sides of the ring core 33 there are arranged pole shoes 35 and 36. The latter are embedded together with the core .33 in a filling material. The pole shoe 36 is in contact with the angle 3 1. A further angle member 38 is connected by bolts 37 to the locking bolt 23 and is so adjusted that when the bolt 23 is in locked position leg 39" thereof is separated by a small air gap from the pole shoe 35.

in the door leaf l a magnetic system 40 is centrally secured about the locking bolt 23 protruding into this leaf by angle pieces 4-8. This magnetic system ll) consists of an iron frame 41 to which are connected anisotropic permanent magnets 42, 43, 44 and 45 with their south poles contacting the iron core 41 and with their north poles connected with a middle part 46 of magnetically conductive material. Moreover a bushing 47 of magnetically non-conductive material is secured to the north pole surfaces of the magnets 42-45, this bushing serving as a locking member for the locking bolt 23. The boring of the middle part 46 is somewhat larger than the boring in the bushing 47 in order that the locking bolt 23 does not touch the middle part 46 in the locked position of the door leaf.

Obviously magnetic leakages occur between the locking bolt 23 and the mass of the door. For the required saturation of the element 32 a predetermined magnetic flux in the locking bolt 23 is necessary. Therefore the magnetic system 40 must be dimensioned in such a manner that the saturation of the element 32 is attained in spite of leakages at any time. By the mentioned arrangement of the magnet system 40 the magnetic flux is introduced into the locking bolt 23 in radial direction. This reduces to a minimum the magnetic leakages from the system it? to the door mass and is advantageous for the dimensioning of the magnet system.

The door post 2 further has an opening 50 through which projects a part 51 of the casing 20 in such manner that the front surface of this part 51 lies flush with the outer surface of the door post 2. The part 51 has a recess 52 provided with a boring 53. An iron member 54 is pressed into the recess 52. This iron member 54 carries an angle iron 55 to which is attached an element 56 for checking the closing of the door leaf 1. This element 56 comprises a core 57 of magnetically saturable material and a winding 6%) on core 57 and pole shoes 58 and 59. The core 57, the pole shoe 525 and the pole shoe 5? are embedded in a filling mass. The pole shoe is in contact with the angle member 55 and the pole shoe 59 touches an iron member 61 welded to the angle member 31.

Opposite the iron member 54 the door leaf 1 is provided with an opening 65 housing a further magnetic system covered by a box 66 weldedto the door leaf. This magnetic system comprises an anistropic permanent magnet 69 secured to the box 66 through an iron disc 68 and a screw 67 ofmagnetically non-conductive material in such manner that its south pole contacts the box 66.

It shall now be assumed that a passenger enters the cabin behind the illustrated door leaf 1, that this door leaf 1 is closed and that the push buttonof the terminal stop has been actuated. The magnet 69 produces a magnetic flux flowing from the north pole of magnet 69 through the iron disc58, the air gap 6 between the door leaf 1 and the door post 2, th'e iron member 54, the angle member 55, the element 56, the angle member 31, theair gap 6, the front surface of the door leaf 1 and the box 66 to the south pole of the magnet 69. This flux saturates the saturable core 57 in element 56 so that analternating current applied to the winding 60 may pass therethrough. This signal influences the elevator control in such manner that the slide rail secured to the cabin operates the lever 21 and'thereby the locking bolt 23 in a locking sense wherein the locking bolt 23 enters the magnetic system 40.

As soon as this position of the locking bolt 23 is attained a directed magnetic flux flows from the anisotropic permanent magnets 42, 43, 44 and 45 over the middle part 46, the small air gap between the latter and the locking bolt 23 to the latter. This magnetic flux then flows from the locking bolt 23 through the angle member 33, the element 32, the angle member 31, the front surface of the door post 2, the air gap 6, the front surface of the door leaf 1, the angle member 48 and the iron rail 41 to the south poles of the magnets i245. Thereby the saturable core 33 is saturated and an alternating current applied to the winding 34 may pass therethrough. This A.C. signal now influences the elevator control in such manner that the elevator cabin may start its travel.

By connecting the south poles of the magnets 42-45 with ground it is obtained that the magnetic flux through the air gap 6 is guided over the very large front surfaces of the door leaf 1 and of the door post 2. Since it is well known that the magnetic resistance decreases with increasing surface such arrangement is advantageous for the dimensioning of said magnets. The same advantage is obtained by thea'rrangement of the south pole of the magnet 6910 ground.

As the elevator cabin reaches the terminal stop the elevator control operates the slide rail secured to the cabin so that the locking bolt .23 is unlocked. The leg 39 of the angle piece 38 moves away from the pole shoe 35 of element 32 so that the magnetic flux is'interrupted and the alternate current applied to the winding 34 may no longer pass. This signal change locks the elevator control so that the cabin may not eifect a further. travel.

Faulty closing of the door lock .is impossible in the arrangement according to the .invention for the following reasoni It is assumed that for example owing to a shortcircuit in the winding 60 it is possible for thealternating current to pass even with the core 57 not saturated as the door is open. This results in operation of the slide rail secured to the cabin and to the locking bolt 23 being displaced in direction of locking. Since, however, owing to the open door the flux of themagnetic system (it) cannot act onto the locking bolt 23 the core 33 remains unsaturated so that the alternating current cannot pass through the winding 34v and travel of the. cabin is prevented.

It is well known that the signals for checking the closing and locking of the door may be simulated in the actually usedsafety devices, for shaft doors, i.e. that it is possible for example by bridging the .door contacts by a wire to render possible a travel of the elevator even with the shaft door open. In. the. arrangement according to the invention such simulation is renderedvery difficult since it is only possible by means of twomagnets correspondinggeometrically-exactly tothe magnets- 40 and 69 in the door leaf.

What I claim is:

1. In a safety means between the stationary. and the movable parts of the shaft doorwof annelevator which parts are adapted forbeinglocked t-ogetherby a locking bolt, the safety means having a device for sensing the closing of the door and a device for. sensing the locking of the door, and whereinthe. elevator is controlled by at least one of the .two devices. by meansof contactless switching elements, the provisionof a body of magnetically saturable material in each of the devices, a winding on each said body and amagnetic system for each device secured in the movable door par-t and adapted to influence the respective body of the associated system, whereby magnetic flux flowing over .the. locking bolt, the saturable body and an air gap between the stationary and the movable door part produces at least a partial saturation of the bodies, which is eifective to .producea signal which is modified by movement of the locking bolt only when the movable door part is locked to the stationary door by the lockingbolt, one of the magnetic systems including four anisotropic permanent magnets projecting into the movable door part and arranged with a flux direction which is radial with respect to the bolt, each of said magnets having a pole which is grounded.

2. A safety means as claimed in claim 1, wherein the other of the magnetic systems also includes anisotropic permanent magnets, and the common poles of .each of the magnetic systems are connected to a common mass.

References Citedin the file of this patent UNITED STATES PATENTS 1,344,430 Wigmore et a1 June 22, 1920 1,453,073 Laureyns a Apr. 23, 1923 2,378,218 Hard June 12, 1945 2,624,792 Fruh Jan. 6, 1953 2,877,361 Chase Mar. 10, 1959 2,989,148 Moser June 20, 1961 FOREIGN PATENTS 691,555 Great Britain May 13, 1953 612,820 Canada Ian. 17, 1961 

1. IN A SAFETY MEANS BETWEEN THE STATIONARY AND THE MOVABLE PARTS OF THE SHAFT DOOR OF AN ELEVATOR WHICH PARTS ARE ADAPTED FOR BEING LOCKED TOGETHER BY A LOCKING BOLT, THE SAFETY MEANS HAVING A DEVICE FOR SENSING THE CLOSING OF THE DOOR AND A DEVICE FOR SENSING THE LOCKING OF THE DOOR, AND WHEREIN THE ELEVATOR IS CONTROLLED BY AT LEAST ONE OF THE TWO DEVICES BY MEANS OF CONTACTLESS SWITCHING ELEMENTS, THE PROVISION OF A BODY OF MAGNETICALLY SATURABLE MATERIAL IN EACH OF THE DEVICES, A WINDING ON EACH SAID BODY AND A MAGNETIC SYSTEM FOR EACH DEVICE SECURED IN THE MOVABLE DOOR PART AND ADAPTED TO INFLUENCE THE RESPECTIVE BODY OF THE ASSOCIATED SYSTEM, WHEREBY MAGNETIC FLUX FLOWING OVER THE LOCKING BOLT, THE SATURABLE BODY AND AN AIR GAP BETWEEN THE STATIONARY AND THE MOVABLE DOOR PART PRODUCES AT LEAST A PARTIAL SATURATION OF THE BODIES, WHICH IS EFFECTIVE TO PRODUCE A SIGNAL WHICH IS MODIFIED BY MOVEMENT OF THE LOCKING BOLT ONLY WHEN THE MOVABLE DOOR PART IS LOCKED TO THE STATIONARY DOOR BY THE LOCKING BOLT, ONE OF THE MAGNETIC SYSTEMS INCLUDING FOUR ANISOTROPIC PERMANENT MAGNETS PROJECTING INTO THE MOVABLE DOOR PART AND ARRANGED WITH A FLUX DIRECTION WHICH IS RADIAL WITH RESPECT TO THE BOLT, EACH OF SAID MAGNETS HAVING A POLE WHICH IS GROUNDED. 